HMS Hector was the lead ship of the Hector-class armoured frigates ordered by the Royal Navy in 1861.

She usually served as Queen Victoria's guard ship when the sovereign was resident at her vacation home on the Isle of Wight.

The Hector-class ironclads,[Note 1] like their immediate predecessors, the Defence-class, were designed as smaller and cheaper versions of the Warrior-class armoured frigates.

[1] The hull was subdivided by watertight transverse bulkheads into 92 compartments and had a double bottom underneath the engine and boiler rooms.

[3] The ships were designed with a very low centre of gravity and had a metacentric height of 4 feet 6 inches (1.4 m).

[4] Hector had one 2-cylinder horizontal return connecting rod steam engine made by Robert Napier and Sons driving a single 20-foot (6.1 m) propeller.

The ship carried 450 long tons (460 t) of coal,[5] enough to steam 800 nautical miles (1,500 km; 920 mi) at full speed.

Firing tests carried out in September 1861 against an armoured target, however, proved that the 110-pounder was inferior to the 68-pounder smoothbore gun in armour penetration and repeated incidents of breech explosions during the Battles for Shimonoseki and the Bombardment of Kagoshima in 1863–1864 caused the navy to withdraw the gun from service shortly afterwards.

[11] The Hector-class ships had a wrought-iron waterline armour belt, 4.5 inches (114 mm) thick, that covered 216 feet (65.8 m) amidships and left the bow and stern unprotected.

To protect against raking fire the belt was closed off by 4.5-inch transverse bulkheads at each end at lower deck level.

Hector became the first British warship to have wireless telegraphy installed when she conducted the first trials of the new equipment for the Royal Navy.